Knife for self-binder knotters



M. M. ARNDT.

KNIFE FOR SELF BINDER KNOTTERS.

APPLICATION FILED OCT. II, 1920.

Patented May 2,1922.

MaximflliunM ArndT axrrirrnron ARNDT, or un vrrowoe, WISCONSIN.

KNIFE FOR SELF-BINDER KNOTTERS.

Specification of Letters Patent.

- Patented May 2, 1922.

Application filed October 11, 1920. Serial No. 416,232.

To all whom it may concern. Be it known that I, MAXIMILLION VI. ARNDT, a citizen of the United States, and resident of Manitowoc, in the county of Manitowoc and State of \Visconsin, have invented certain new and useful Improvements in Knives for Self-Binder Knotters; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention has for its object to provide a simple, economical and positively func tioning twine cutting knife for that type of self-binder mechanisms, wherein a swinging arm under cam control is utilized for carrying the knife. In this standard type of knife, as for example used in the binder for which patent was issued to John F Appleby, Sept. 17, 1878, No. 208,137, for grain binders, the cutting edge of the knife is tangentially disposed with relation to the axis of the arm upon which it is mounted. Hence practice has demonstrated that the tendency of the twine is to slip 0H and fail to be severed after the knot is formed, unless constant care is had to keep the knife at a fine cutting edge. Obviously where the twine is not severed between the bundles, much difficulty is incurred, and a shedding of the twine from the end of the knife is a constant source of trouble to those operating such binders.

My invention is therefore particularly designed to overcome this difficulty, and with this in view, I provide some type of recess at the shedding end of the knife whereby the twine will be positively caught and severed, irrespective of the dullness of the blade.

With the above object in view, the invention consists in certain peculiarities in the shape of the cutting edge of the blade as herein set forth. Referring to the drawing,

Figure 1 illustrates a standard knotter mechanism arm which is pivoted upon the knotter bracket and actuated by a cam wheel, not shown, the arm being provided with a knife embodying the features of my invention, and g I Figure 2 is a detail cross section through the knife and lower portion of the arm, this section being indicated by section line 2--2 of Figure 1.

Referring by characters to the drawing, 1

represents the knife carrying arm provided wlth a usual hub 2 constituting the pivot po nt of the arm and a short extension carrylng a cam roller 3. The lower portion of the arm is provided with a pad 4 for the receptlon of a foot 50f the knife blade 6, the foot being extended at approximately a right angle to the blade portion. The foot in this instance is shown secured by rivets, but obviously it may be fastened in any suitable manner, and it should be understood that the knife is arranged to fit the standard parts of the arm in such manner that the standard blades, now used, can be removed and the lfalade under consideration substituted there- As best shown in Figure 1 of the drawing, the knife or blade 6 is disposed radially with relation to the axis of the arm and has its main cutting edge 7 slightly crowned and extended substantially tangentially with relation to the arm axis. This tangential cutting face or edge is positioned approximately in the same general plane as the standard knives heretofore mentioned. As shown in this exemplification of my invention, the inner end of the cutting edge 7 is. provided with a head 8 which overhangs the cutting edge 7 and said head is provided with a cutting edge 7 which intersects the cutting edge 7 at an acute angle to thus form a tooth or recess, preferably V-shaped. By employing a tooth recess of this character at the end of the cutting edge of the knife 7, obviously it will be seen that should the twine tend to shed over the inner end of said cutting edge, it will, irrespective of the cutting surface, grip between the faces of the recess which will tend to bite upon the cord and thus positively sever it, even though the knife blade is comparatively dull at the points men tioned.

I claim:

1. In a self-binder knotter mechanism having a pivoted blade carrying arm, and a twine cutting blade therefor, the same being disposed radially with respect'to the axis of the arm, and having its cutting edge inclined substantially tangentially with respect to the arm axis, the cutting edge being terminated with a toothed end.

. 2. In a self-binder knotter mechanism having a pivoted blade carrying arm and a twine cutting blade therefor, the same being disposed radially With respect to the axis of the arm and having its cutting edge inclined substantially tangentially with respect to the arm axis, the inner end of the knife being formed with a head having a V-shaped recess have hereunto set my hand at Manitowoc, in

the county of Manitowoc and State of Wisconsin.

MAXIMILLION M. ARNDT. 

